P27 CRITICAL STUDY OF HAIR GROWTH ANALYSIS WITH COMPUTER ASSISTED METHODS
Trüeb RM1 and Van Neste D2
1Department of Dermatology, University Hospital of Zurich, Switzerland
2Skinterface, Tournai, Belgium

Computer assisted image analysis has been proposed for human hair growth studies. The performances of Trichoscan, a commercially available automated system combining epiluminescence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness, and hair fibre crossing. Most of these problems have been identified in the late 80ies and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials.